And then Trump appeared with CNN's Anderson Cooper. When asked about Trump's ongoing feud with Ted Cruz, which recently brought in their wives, the real-estate mogul answered, "I didn't start it," an answer that Cooper compared to a 5-year-old's response.

"Donald Trump does act like a 5-year-old," Colbert declared of the analogy. "But that's why people like him."

Colbert wanted to speak to the candidate about the recent campaign hiccups, but he wasn't available. So the "Late Show" host, who thinks that Trump has become "a cartoonish version of himself," did the next best thing.

"So instead, we invited a slightly less cartoonish version," he announced before bringing out "Cartoon Donald Trump."

When Colbert tried to get some reasoned explanation from the animated Trump, he received only childish responses.

For example, when the host called him out for sounding immature, Cartoon Trump responded, "I know you are, but what am I?"

And Cartoon Trump also had the most inventive way of threatening legal action: "I'm rubber, you're glue. I have a lawyer and I will sue."